When you use the vSphere Client to view storage devices available to your ESX/ESXi host and the output differs from what you expect, perform troubleshooting tasks.

Perform the following troubleshooting tasks if you have display issues.

Troubleshooting iSCSI LUN Display

Troubleshooting Task


Check cable connectivity.

If you do not see a port, the problem could be cable connectivity or routing. Check the cables first. Ensure that cables are connected to the ports and a link light indicates that the connection is good. If each end of the cable does not show a good link light, replace the cable.

Check routing settings.

Controls connectivity between different subnets on your Ethernet configuration. If your ESX/ESXi system and iSCSI storage are not on the same subnet, ensure that appropriate routing exists between the subnets. Also, ensure that the subnet mask and gateway address are set correctly on the iSCSI storage and the iSCSI initiator in the ESX/ESXi host.

Check access control configuration.

If the expected LUNs do not appear after rescan, access control might not be configured correctly on the storage system side:

If CHAP is configured, ensure that it is enabled on the ESX/ESXi host and matches the storage system setup.

If IP-based filtering is used, ensure that the iSCSI HBA or the VMkernel port group IP address and service console IP address are allowed.

If you are using initiator name-based filtering, ensure that the name is a qualified iSCSI name and matches the storage system setup.

For booting from a SAN, ensure that each ESX host sees only required LUNs. Do not allow any ESX host to see any boot LUN other than its own. Use storage system software to make sure that the ESX host can see only the LUNs that it is supposed to see.

Ensure that the Disk.MaxLUN setting allows you to view the LUN you expect to see.

Check storage processor setup.

If a storage system has more than one storage processor, make sure that the SAN switch has a connection to the SP that owns the LUNs you want to access. On some storage systems, only one SP is active and the other SP is passive until a failure occurs. If you are connected to the wrong SP (the one with the passive path) you might not see the expected LUNs, or you might see the LUNs but get errors when trying to access them.

For software iSCSI, check network configuration.

The software iSCSI initiator in ESX/ESXi requires that a VMkernel network port have access to the iSCSI storage. The software initiator uses the VMkernel for data transfer between the ESX/ESXi system and the iSCSI storage.

Rescan your iSCSI initiator.

Perform a rescan each time you complete the following tasks:

Create new LUNs on a SAN.

Change the LUN masking on an ESX/ESXi host storage system.

Reconnect a cable.

Make a change to a host in a cluster.

Change CHAP settings or add new discovery addresses.